NEW YORK (Reuters) - Americans in Utah, Mississippi, Alabama, Tennessee, South Carolina and Idaho gave the highest percentage of their income to charities in 2008, according to a report released on Monday analyzing the most recent comprehensive data from the Internal Revenue Service.

With two of the top states home to large Mormon populations and seven others comprising the so-called Bible Belt of heavily Protestant Christian states, rates of charitable giving appeared linked to religion, the report said.

"How America Gives," by the nonprofit Chronicle of Philanthropy was based on analysis of charitable donations in all cities and towns in the country, including the various zip codes.

"Religion has a big influence on giving patterns. Regions of the country that are deeply religious are more generous than those that are not," the Chronicle said in a written summary of the findings.

Residents in Utah, where the Church of Jesus Christ of Latter-day Saints is centered in the United States, donated 10.6 percent of money left over after paying taxes and essential expenses, or discretionary income, according to the report.

In Idaho, also known for its large Mormon community, residents gave 6.4 percent of their discretionary income, compared with 2.5 percent in New Hampshire and 2.8 percent in Maine, the bottom two states.

Other top charity givers were southern states such as Mississippi where residents gave 7.2 percent and Alabama, where households gave 7.1 percent. Tennesseans donated on average 6.6 percent and South Carolinians gave 6.4 percent.

Excluding religious donations, New York would move up from the 18th place to second place and Pennsylvania would be in fourth place instead of 40th, the report said. Households in the Northeast donated 1.4 percent of their discretionary income to secular charities whereas in the South households give 0.9 percent.

The report found that households earning $50,000 to $75,000 gave an average of 7.6 percent of their discretionary income to charity while those making $100,000 or more gave an average of 4.2 percent of their income.

The report was based on IRS data taken from those who earned at least $50,000 in 2008.